DIFFERENCES IN MUSCLE MECHANICAL ...

Journal of Strength and Conditioning Research Publish Ahead of Print DOI: 10.1519/JSC.0000000000000803

DIFFERENCES IN MUSCLE MECHANICAL PROPERTIES BETWEEN ELITE POWER AND ENDURANCE ATHLETES: A COMPARATIVE STUDY

Irineu Loturco1 ( ), Saulo Gil1, Cristiano Frota de Souza Laurino2, Hamilton Roschel3,

TE

D

Ronaldo Kobal1, Cesar Cavinato Cal Abad1, Fabio Yuzo Nakamura4

1- NAR - Nucleus of High Performance in Sport, São Paulo, SP, Brazil

2- Brazilian Track & Field Confederation, Medical Department, São Paulo, SP, Brazil

EP

3- School of Physical Education and Sport - University of São Paulo, SP, Brazil

C C

4- State University of Londrina, Londrina, PR, Brazil

Irineu Loturco ( )

NAR - Nucleus of High Performance in Sport.

A

Av. Duquesa de Goiás, 571, Real Parque, 05686-001 – São Paulo, SP, Brazil. Tel.: +55-11-3758-0918 E-mail: [email protected] Running title: Muscle mechanical properties in elite athletes

Copyright Ó Lippincott Williams & Wilkins. All rights reserved.

ABSTRACT

2

The aim of this study was to compare muscle mechanical properties (using

3

tensiomyography - TMG) and jumping performance of endurance and power athletes, and

4

to quantify the associations between TMG parameters and jumping performance indices.

5

Forty-one high-level track and field athletes from power (n=22; mean ± SD age, height, and

6

weight were 27.2 ± 3.6 years; 180.2 ± 5.4 cm; 79.4 ± 8.6 kg) and endurance (endurance

7

runners and triathletes; n=19; mean ± SD age, height, and weight were 27.1 ± 6.9 years;

8

169.6 ± 9.8 cm; 62.2 ± 13.1 kg) specialties had the mechanical properties of their rectus

9

femoris (RF) and biceps femoris (BF) assessed by TMG. Muscle displacement (Dm),

10

contraction time (Tc), and delay time (Td) were retained for analyses. Furthermore, they

11

performed squat jumps (SJ), countermovement jumps (CMJ) and drop jumps to assess

12

reactive strength index (RSI), using a contact platform. Comparisons between groups were

13

performed using differences based on magnitudes and associations were quantified by the

14

Spearman’s ρ correlation. Power athletes showed almost certain higher performance in all

15

jumping performance indices when compared with endurance athletes (SJ = 44.9 ± 4.1 vs.

16

30.7 ± 6.8 cm; CMJ = 48.9 ± 4.5 vs. 33.6 ± 7.2 cm; RSI = 2.19 ± 0.58 vs. 0.84 ± 0.39, for

17

power and endurance athletes, mean ± SD, respectively; 00/00/100, almost certain, P
5%, the true difference was assessed as unclear (7). When

185

data were non-normally distributed, they were transformed by taking the natural logarithm.

186

However, for the sake of clarity and practicality, they were presented in back-transformed

187

values. The spreadsheet made available by Hopkins (14) was used. To quantify the


188

association between the TMG indices and performance in vertical jump tests, Spearman’s ρ

189

(rho) correlation was used due to the distribution of data.

190 191

RESULTS

192

Table 1 shows the performance of power and endurance athletes in the squat jumps

194

and countermovement jumps as well as the reactive strength index. Power athletes

195

performed better in all of them (squat jumps = 44.9 ± 4.1 vs. 30.7 ± 6.8 cm;

196

countermovement jumps = 48.9 ± 4.5 vs. 33.6 ± 7.2 cm; reactive strength index = 2.19 ±

197

0.58 vs. 0.84± 0.39, for power and endurance athletes respectively; 00/00/100, almost

198

certain, P< 0.05). In addition, power athletes performed better in the components of

199

reactive strength index, namely the drop jump height (45.9 ± 5.0 vs. 33.0 ± 6.8 cm;

200

00/00/100, almost certain, P< 0.05) and contact time (218.5 ± 49.9 vs. 431.1 ± 117.5 ms;

201

00/00/100, almost certain, P< 0.05). Results were similar when comparing endurance

202

runners and sprinters (data not shown). Figure 2 depicts the differences in Tc and Td (panel

203

A) and Dm (panel B) for both muscle groups (RF and BF) between power and endurance

204

athletes (Tc BF = 14.3 ± 2.3 vs. 19.4 ± 3.3 ms; Dm BF = 1.67 ± 1.05 vs. 4.23 ± 1.75 mm;

205

Td BF = 16.8 ± 1.6 vs. 19.6 ± 1.3 ms; Tc RF = 18.3 ± 2.8 vs. 22.9 ± 4.0 ms; Dm RF = 4.98

207

TE

EP

C C

A

206

D

193

± 3.71 vs. 8.88 ± 3.45 mm; Td RF = 17.5 ± 1.0 vs. 20.9 ± 1.6 ms, for power and endurance athletes respectively; 00/00/100, almost certain, P< 0.05).

208 209

***INSERT TABLE 2 HERE***

210


***INSERT FIGURE 2 HERE***

211 212

When pooling the power and endurance athletes’ data, the Spearman’s ρ (rho)

214

correlations were moderate and significant between Tc BF (ρ = -0.61), Td BF (ρ = -0.65),

215

Td RF (ρ = -0.71) and squat jumps. A moderate correlation was also found between Td RF

216

and countermovement jumps (ρ = -0.72), and between Td BF (ρ = -0.63), Td RF (ρ = -0.66)

217

and reactive strength index. When considering only endurance runners and sprinters,

218

similar results were obtained (data not shown).

220

DISCUSSION

EP

221

TE

219

D

213

We hypothesized that mechanical muscle properties and vertical jumping

223

performance would be able to discriminate power and endurance athletes. In the case of

224

confirming the first hypothesis, a significant correlation between TMG parameters and

225

jumping performance could exist. Findings reported herein are in accordance with our

226

hypotheses (i.e., athlete-type discrimination ability using TMG and jump tests, and

227

significant correlation between them). This is the first study to show these findings in elite

229

A

228

C C

222

athletes.

Vertical jump tests are widely used to train and test professional athletes (1, 6). As

230

the results are strongly associated with strength and power measures (30), it is conceivable

231

that, in our sample of elite athletes, the power group would be able to jump significantly

232

higher than the endurance group. This is consistent with the findings of Vuorimaa et al

233

(29), who reported higher countermovement jumping performance in sprinters (55.0 ± 5.5


cm) when compared with both marathon runners (31.2 ± 3.1 cm) and middle-distance

235

runners (43.8 ± 4.0 cm), reflecting the well-known differences in muscle fiber composition

236

(2, 8), neuromechanical properties (12) and long-term training related adaptations (9)

237

across these athletes. Importantly, such differences in performance are commonly observed

238

in the literature when comparing samples of power and endurance oriented training athletes

239

(5, 28).Within an elite group of sprinters, vertical jump is highly associated with sprinting

240

performance (17). This result supports the relevance of assessing jump performance in this

241

population.

TE

D

234

Moreover, as contact time is an important factor in determining sprinting speed

243

(22), it was expected that the power athletes, who are capable of jumping higher and

244

generating more impulse (impulse = force x time), would present significantly higher

245

reactive strength index than endurance athletes. This is in line with the fact that power

246

athletes are stronger than endurance runners, even after correcting their maximum strength

247

of leg extensors to body mass (unpublished data). The stronger athletes studied

248

outperformed their weaker peers in drop jump height, contact time and reactive strength

249

index, thus confirming previous findings (3). Therefore, sprinters (and possibly jumpers

250

and throwers) have to target training strategies aimed at adapting their neuromuscular

251

system in order to manifest better reactive strength than athletes from other specialties in

253

C C

A

252

EP

242

track and field, such as middle- and long-distance runners). Nevertheless, endurance athletes should not neglect neuromuscular development leading to increased explosive

254

power due to its contribution to enhanced running economy and time-trial performance

255

(23).

256

Finally, the absence of differences in the countermovement jumps and squat jumps

257

ratio between the power and endurance groups might be due to the elite level of the athletes


(13, 19). It is important to emphasize that our sample comprised national and international

259

competitors and, even in the group of endurance athletes, the efficiency of the stretch-

260

shortening cycle is crucial to sports performance, due to the aforementioned factors.

261

Nowadays, most coaches and athletes are aware of the effectiveness of concurrent

262

endurance and explosive type strength training on neuromuscular and endurance

263

performance (21). For instance, in a study by Ramirez-Campillo et al (25), highly

264

competitive middle- and long-distance runners improved their 2.4 km time trial, sprinting

265

ability and performance in countermovement jumps and drop jumps after explosive type

266

training, although the control group did not demonstrate any improvement. Therefore,

267

depending on the training methods adopted, endurance runners are able to present similar

268

countermovement jump and squat jump ratios compared to power athletes, regardless of

269

lower vertical jumping performance in isolation.

EP

TE

D

258

The differences in the muscle fiber type composition between power and endurance

271

athletes have been reported (2, 8). As Simunic et al (27) found significant correlations

272

between muscle mechanical parameters and muscle fiber type composition, the differences

273

in Tc, Td, and Dm between power and endurance athletes reported in the present study

274

were consistent with our expectations. Moreover, the present study confirms the validity of

275

TMG in discriminating groups of athletes at the extremes of human performance (i.e.,

277

A

276

C C

270

sprint and endurance). Rey et al (26) have previously shown this capability of discriminating athletes. In spite of soccer players being more homogeneous in physical

278

terms compared to track & field athletes, Tc was greater in external defenders than central

279

defenders and goalkeepers for RF. This is possibly linked to the positional roles of central

280

defenders and goalkeepers, who are required to jump and dive to a greater extent than

281

central defenders. Recently, TMG was shown to be sensitive enough to discriminate sex


and lateral symmetry in top-level kayakers (10) and track adaptations over the course of a

283

season in road cyclists (11). Curiously, both power (18.3 ± 2.8 ms) and endurance groups

284

(22.9 ± 4.0 ms) in the present study presented faster Tc of RF than the road cyclists (35.5-

285

46.7 ms). This means that the contractile properties of track and field athletes are

286

phenotypically faster than those found in road cyclists, in spite of endurance runners (8.88

287

mm) resembling the Dm of cyclists (7.4-8.8 mm), implying similar muscle tone and tendon

288

stiffness. The Tc of athletes in our sample was also shorter than those found in soccer

289

players (25.80-31.52 ms), while soccer players presented slightly higher Dm (10.82-11.72

290

mm). Finally, Td RF (17.5 ± 1.0 and 20.9 ± 1.6 ms in power and endurance athletes,

291

respectively) were shorter in our athletes than in soccer players (24.22-26.55 ms),

292

suggesting that muscle activation time is optimized in both power and endurance track and

293

field athletes.

EP

TE

D

282

To the best of our knowledge, this is the first investigation to observe significant

295

correlations between muscle mechanical responses and vertical jumping ability in elite

296

athletes. This is contrary to our previous (unpublished) observations in soccer players. It is

297

possible that the wide range of technical and physical characteristics that determine success

298

in team-sports affect performance in specific assessments, including the vertical jump tests.

299

Also, soccer players are more likely to be “mixed” in terms of fiber type composition (20),

301

A

300

C C

294

compared to track & field athletes. Consequently, the TMG parameters may not be strongly associated with jumping performance in team sport athletes. On the other hand, the “natural

302

and specific talent” of track & field endurance and/or power athletes is capable of

303

producing consistent outcomes in these tests, more strongly related to their endowments

304

and specific training history, increasing the values of associations with the neuromechanical

305

characteristics evaluated by TMG parameters.


306 307

PRACTICAL APPLICATIONS

308

The findings demonstrate that power athletes are able to perform better than

310

endurance athletes in vertical jumping tests and in the components of the reactive strength

311

index (i.e., drop jump height and contact time) supporting the use of these tests to

312

discriminate between athletes more prone to excel in the extremes of human performance

313

(endurance and power athletes). Furthermore, the present results suggest that the muscle

314

mechanical properties assessed by TMG could provide important information regarding the

315

athlete-type discrimination, especially in modalities that involve power and endurance

316

abilities, such as track & field sports. The combination of TMG and explosive testing can

317

help professionals to screen the functional abilities and physical characteristics of their

318

athletes. Finally, the relationships between muscle mechanical properties and other

319

performance measures (i.e., sprinting speed and changing-of- direction ability), as well as

320

the potential to identify talents among young and prospective athletes must be further

321

investigated.

C C

EP

TE

D

309

322

324 325

REFERENCES

A

323

1.

Adams K, O' Shea KL, and Climstein M. The effects of six weeks of Squat,

326

Plyometric, and Squat-Plyometric Training on Power Production. J Appl Sports Sci

327

Res 6: 36-41, 1992.


328

2.

Baguet A, Everaert I, Hespel P, Petrovic M, Achten E, and Derave W. A new

329

method for non-invasive estimation of human muscle fiber type composition. PLoS

330

One 6: e21956, 2011. 3.

when performing drop jumps. J Strength Cond Res 28: 373-380, 2014. 4.

Int J Sports Physiol Perform 1: 50-57, 2006.

334 335

Batterham AM and Hopkins WG. Making meaningful inferences about magnitudes.

5.

D

332 333

Barr MJ and Nolte VW. The importance of maximal leg strength for female athletes

Boullosa DA, Tuimil JL, Alegre LM, Iglesias E, and Lusquinos F. Concurrent

TE

331

336

fatigue and potentiation in endurance athletes. Int J Sports Physiol Perform 6: 82-

337

93, 2011. 6.

Buchheit M, Mendez-Villanueva A, Delhomel G, Brughelli M, and Ahmaidi S.

EP

338 339

Improving repeated sprint ability in young elite soccer players: repeated shuttle

340

sprints vs. explosive strength training. J Strength Cond Res 24: 2715-2722, 2010. 7.

repeated sprint and jump ability test. Int J Sports Physiol Perform 5: 3-17, 2010.

342 343

Buchheit M, Spencer M, and Ahmaidi S. Reliability, usefulness, and validity of a

C C

341

8.

Costill DL, Daniels J, Evans W, Fink W, Krahenbuhl G, and Saltin B. Skeletal muscle enzymes and fiber composition in male and female track athletes. J Appl

345

Physiol 40: 149-154, 1976.

346 347

A

344

9.

plyometric training frequency produces greater jumping and sprinting gains compared with high frequency. J Strength Cond Res 22: 715-725, 2008.

348 349

de Villarreal ES, Gonzalez-Badillo JJ, and Izquierdo M. Low and moderate

10.

García-García O, Cancela-Carral JM, and Huelin-Trillo F. Neuromuscular profile of

350

top level women kayakers, assessed through tensiomyography. J Strength Cond Res

351

in press, 2014.


352

11.

Garcia-Garcia O, Cancela-Carral JM, Martinez-Trigo R, and Serrano-Gomez V.

353

Differences in the contractile properties of the knee extensor and flexor muscles in

354

professional road cyclists during the season. J Strength Cond Res 27: 2760-2767,

355

2013.

356

12.

Hakkinen K, Mero A, and Kauhanen H. Specificity of endurance, sprint and strength training on physical performance capacity in young athletes. J Sports Med

358

Phys Fitness 29: 27-35, 1989. 13.

Harrison AJ, Keane SP, and Coglan J. Force-velocity relationship and stretch-

TE

359

D

357

360

shortening cycle function in sprint and endurance athletes. J Strength Cond Res 18:

361

473-479, 2004. 14.

1-7, 2004.

363 364

Hopkins WG. How to interpret changes in an athletic performance test. Sportsci 8:

15.

EP

362

Hudgins B, Scharfenberg J, Triplett NT, and McBride JM. Relationship between jumping ability and running performance in events of varying distance. J Strength

366

Cond Res 27: 563-567, 2013.

367

16.

C C

365

Krizaj D, Simunic B, and Zagar T. Short-term repeatability of parameters extracted from radial displacement of muscle belly. J Electromyogr Kinesiol 18: 645-651,

369

2008.

370 371

A

368

17.

and Nakamura FY. Relationship between sprint ability and loaded/unloaded jump tests in elite sprinters. J Strength Cond Res in press, 2014.

372 373 374

Loturco I, D'Angelo RA, Fernandes V, Gil S, Kobal R, Abad CCC, Kitamura K,

18.

Malina RM. Physical growth and biological maturation of young athletes. Exerc Sport Sci Rev 22: 389-433, 1994.


375

19.

McGuigan MR, Doyle TL, Newton M, Edwards DJ, Nimphius S, and Newton RU.

376

Eccentric utilization ratio: effect of sport and phase of training. J Strength Cond Res

377

20: 992-995, 2006.

378

20.

Metaxas TI, Mandroukas A, Vamvakoudis E, Kotoglou K, Ekblom B, and Mandroukas K. Muscle fiber characteristics, satellite cells and soccer performance

380

in young athletes. J Sports Sci Med 13: 493-501, 2014.

381

21.

D

379

Mikkola JS, Rusko HK, Nummela AT, Paavolainen LM, and Hakkinen K. Concurrent endurance and explosive type strength training increases activation and

383

fast force production of leg extensor muscles in endurance athletes. J Strength Cond

384

Res 21: 613-620, 2007. 22.

Morin JB, Edouard P, and Samozino P. Technical ability of force application as a

EP

385

TE

382

386

determinant factor of sprint performance. Med Sci Sports Exerc 43: 1680-1688,

387

2011. 23.

Paavolainen L, Hakkinen K, Hamalainen I, Nummela A, and Rusko H. Explosive-

C C

388 389

strength training improves 5-km running time by improving running economy and

390

muscle power. J Appl Physiol 86: 1527-1533, 1999.

391

24.

characteristics and fatigue in endurance and sprint athletes during a new anaerobic

394

A

392 393

Paavolainen L, Hakkinen K, Nummela A, and Rusko H. Neuromuscular

power test. Eur J Appl Physiol Occup Physiol 69: 119-126, 1994.

25.

Ramirez-Campillo R, Alvarez C, Henriquez-Olguin C, Baez EB, Martinez C,

395

Andrade DC, and Izquierdo M. Effects of plyometric training on endurance and

396

explosive strength performance in competitive middle- and long-distance runners. J

397

Strength Cond Res 28: 97-104, 2014.


398

26.

limb muscles in professional soccer players. J Electromyogr Kinesiol, 2012.

399 400

Rey E, Lago-Penas C, and Lago-Ballesteros J. Tensiomyography of selected lower-

27.

Simunic B, Degens H, Rittweger J, Narici M, Mekjavic IB, and Pisot R.

401

Noninvasive estimation of myosin heavy chain composition in human skeletal

402

muscle. Med Sci Sports Exerc 43: 1619-1625, 2011.

training background on jumping height. J Strength Cond Res 21: 848-852, 2007.

404 405

Ugrinowitsch C, Tricoli V, Rodacki AL, Batista M, and Ricard MD. Influence of

D

28.

29.

Vuorimaa T, Hakkinen K, Vahasoyrinki P, and Rusko H. Comparison of three

TE

403

406

maximal anaerobic running test protocols in marathon runners, middle-distance

407

runners and sprinters. Int J Sports Med 17 Suppl 2: S109-113, 1996. 30.

Wisloff U, Castagna C, Helgerud J, Jones R, and Hoff J. Strong correlation of

EP

408 409

maximal squat strength with sprint performance and vertical jump height in elite

410

soccer players. Br J Sports Med 38: 285-288, 2004.

411

414 415 416 417 418

C C

413

TABLES AND FIGURES LEGENDS

Table 1. Characteristics of the subjects. Data are presented as mean ± standard deviation.

A

412

Table 2. Performance in the squat jump (SJ) and countermovement jump (CMJ), the ratio between SJ and CMJ (SJ/CMJ) and the reactive strength index (RSI) in power and endurance athletes. Data are presented as mean ± standard deviation.

419 420

Figure 1. TMG displacement sensor placed above the rectus femoris, with the two

421

electrodes used for muscle electrical stimulation.


422

Figure 2.Contraction time (Tc), delay time (Td) (A), and displacement (Dm) (B) of the

424

biceps femoris (BF) and rectus femoris (RF) derived from tensiomyography in power and

425

endurance athletes. Data are presented as mean ± standard deviation. The quantitative

426

chances were assessed qualitatively as follows:99%, almost certain;*00/00/100, almost certain;(P < 0.05).

D

423

TE

429 430 431

EP

432 433 434

A

C C

435


Table 1. Characteristics of the subjects. Data are presented as mean ± standard deviation. Height (cm)

Weight (kg)

Power (n=22)

27.2 ± 3.6

180.2 ± 5.4

79.4 ± 8.6

Endurance (n=19)

27.1 ± 6.9

169.6 ± 9.8

62.2 ± 13.1

A

C C

EP

TE

D

Age (years)


Table 2. Performance in the squat jump (SJ) and countermovement jump (CMJ), the ratio between SJ and CMJ (SJ/CMJ) and the reactive strength index (RSI) in power and endurance athletes. Data are presented as mean ± standard deviation. Power

Endurance

SJ (cm)

44.9 ± 4.1*

30.7 ± 6.8

% Chance +/Trivial/100/00/00

CMJ (cm)

48.9 ± 4.5*

33.6 ± 7.2

100/00/00

Almost Certain

CMJ/SJ

1.09 ± 0.05

1.10 ± 0.08

12/42/43

Unclear

RSI (cm/ms)

2.19 ± 0.58*

0.84 ± 0.39

100/00/00

Almost Certain

Qualitative Inference Almost Certain

A

C C

EP

TE

D

The quantitative chances were assessed qualitatively as follows: 99%, almost certain; (*P < 0.05).


D TE EP C C A Copyright Ó Lippincott Williams & Wilkins. All rights reserved.

D TE EP C C A Copyright Ó Lippincott Williams & Wilkins. All rights reserved.